Mode-space energy distribution in instability-driven plasma turbulence
Mode-space energy distribution in instability-driven plasma turbulence
复制标题
不稳定驱动等离子体湍流中的模式空间能量分布
DOI：
10.1063/1.4903207
复制
发表时间：
2014
影响因子：
2.2
通讯作者：
F. Merz
中科院分区：
文献类型：
--
作者：
P. Terry;K. Makwana;M. Pueschel;D. Hatch;F. Jenko;F. Merz
研究了回旋运动离子温度梯度驱动湍流中阻尼模的能量转移，以了解转移动力学，并找到密集模式空间的标度表示。适当的正交和线性本征模分解的介绍和检查，以评估模式是否得到很好的解决，以及它们所包含的尺度。据观察，阻尼模式在一个范围内的非均匀尺度接收能量的同时，直接从不稳定的模式，构成一种形式的并行传输，不同于串行模式到模式的水动力湍流的波数级联传输。控制的模式，以及解决和标记的线性分解的模式，以阻尼率的顺序，在模式空间中的能量传递满足均分的能量耗散率，导致一个简单的规则的阻尼模式的空间中的能量分布。能量耗散率均分是正则非线性方程的形式。
Energy transfer to damped modes in gyrokinetic ion temperature gradient driven turbulence is studied to understand the transfer dynamics and find scaling representations for the heavily populated mode space. Proper orthogonal and linear eigenmode decompositions are introduced and examined to assess whether modes are well-resolved and what scales they encompass. It is observed that damped modes across a range of inhomogeneous scales receive energy simultaneously and directly from the unstable mode, constituting a form of parallel transfer, distinct from the serial mode-to-mode transfer of the wavenumber cascade of hydrodynamic turbulence. Controlling for modes that are well resolved and labeling the modes of the linear decomposition in order of damping rate, energy transfer in the mode space satisfies an equipartition of the energy dissipation rate, leading to a simple rule for the distribution of energy in the space of damped modes. Energy dissipation rate equipartition is the form that the canonical nonl...